Shock absorber



J. P. BALDWIN SHOCK ABSORBER Aug. 9, 1927. 1,638,234

Filed July 28, 1925 2 sheets-Sheet 1 Aug, 9,1927.

sHocK ABsoRBE YF'iled July 28, 1925 2 Sheets-$heet 2 l'it.

Patented Aug. 9', 1927.

rit-tiro STATES PATENT oFFicr..

JAMES PIERCE BALnWnL'oF Los ANGELES, cALnoRNIA.

snocx ABsonBR.

' Application med July 2s, 1925. serial No 46,669.

The present invention relates to shock absorbcrs of the 'friction type and particularly to automatic adjusting mechanism therefor. The object of the invention is to provide .fi an accurate and posit-ive adjusting mechanism 'for shock absorbers ci' the friction type generally and Which is @Specially adapted for use in a shock absorber of the Vkind shown in my copending application, Serial v No. 180113, tiled March 24;, 1925. The absorber shown in that application comprises friction shoes operating in a cylindrical casin combination with strut mechanism for causing the shoes to rictional'ly engage the -l casing in one direction of rotation While relieving the friction in the opposite direction. The mechanism of' this absorber is housed in a closed casing adapted to besecured to the trame oi an automobile and after the abfi .sorber has been assembled and tested it is desired that further access to themechanism tor adjustment or any other` purpose be unnecessary. Obviously it the absorber is to have a substantial liile some internal mechaif nism must be provided to automatically take up and looseness that may vdevelop in use. The present invention provides an internal automatic adjusting mechanism for absorbersrctf this type which is positive in itsaction 3*) and which will maintain the absorber in a condition or' accurate adjustment during the lire or the absorber. Y

Several different embodiments or the invention will be described hereinafter from Which its nature and advantages Will be clearly seen by one skilled in the art.

Referring to the accompanying drawings: Fig. 1 is a fragmentary side view of an automobile frame showing a shock absorber, in which the present invention is embodied,

mounted on its front end;

Fig. 2 is a transverse vertical section taken on the line 2-2 of Fig. 1:5

Fig. 3 is al section on the line 4-4 of Fig. d;

Fig. l is a horizontal section through the center ot the absorber;

Fig. 5 is a section on the line 5 5 of rima;

Fig. 6 is a fragmentary sectional view showing aldiiierent form of the invention;

Fig. 7 is a top view of a ratchet member employed in the construction o'f-Fig. 6;

8 is a fragmentary sectional view rf-f showing a further modication; and

Fig. 9 is a side viewof the mechanism shown in Fig. 8. ,v n

The base 10 'of the absorber is formed With perforated ears Which are bolted rto the automobile t'rame. A cylindrical A member 11 having a. neck 12 is threaded into the base 10 at 13,. the parts 10 and vllrbeing thek relatively'stationary or nonerotatable parts of theabsorber and constituting a base or housing in which the rotatable parts are mounted. n j

The rotatable c-ore ,of ther absorber Acomprises a circular, or dislvlike', member 14 having a central boss 15 on Which is threaded the hub 16 of an arm 17 connected by ay ink 17 to a bracket on the car axle, said arm having a circular flange 17 concentric with hub 16 to provide an annular vrecess for the neck 12, suitable gaskets and packing being provided to render the joint liquid tight. Formed on or' attached tothe inner tace of disk 14 are three pairs of triangular members 18, 18gbetween the members of each pair of which Pis mounted a strut seat 19, the side Walls or the seats fitting nicely between the triangular members so that the lseats are restrained from m-ovementfex'cept f in a radial direction. A strut 2O is supported on each of the seats 19. The struts are formed with curved, or .cylindrical` outer endseng'aging correspondingly formed sockets in brake shoes 21 and With suitably curvedinner ends adaptedy kto roll on plane surfaces formed on' seats 19.

riihe brake shoes have suitable leather facings which rub aga-inst the cylindrical inner Wall `of member 11. Te sion devices are provided which tend to hold the stru-ts against the backs ot their respectiveseats 19, said device$-, as clearly shown in Fig. 3, comprising coiled springs 22 provided at one end With heads engaging resilient shims lying against the faces of the struts and at the other end With `conical beads engaging sockets formed in the triangular members 18. The inner faces of seats 19 are inclined, as clearly shown in Fig. 1, and engage correspondingly inciined tace-s et a triangular` abutment member 23, the seats being thus rigidly held against radial movement inwardly. y 1 he absorber, as thus far described, acts in the following manner :--TvVhen`v the car strikesv an obstruction or depression the lsprings S ieX downward and cause arm 1'? and the rotatable parts of the absorber to move in a counter-clockwise direction, looking at Fig. 1; in a clockwise direction, looling at Fig. 3, the latter being a view of the side opposite to that shown in Fig. 1'. Rotating in this direction the absorber offers little resistance to the relative movement be:V

bounding movement with a force which is proportional to the thrust angle.

Due to the wear of the friction parts it is obvious that the effectiveness of the absorber would progressively become less with the extent of use unless some means of adjustment were provided to take up the looseness developed. The present invention is directed to adjusting means for this purpose. Mechanism' embodying the invention will now be described. r

Referring first to the form of the 'invention .shown in Figs. t and 5, it will be observed that the abutment member 23 is threaded on a stem 24e which has a rounded inner' end engaging the center of disk member 14 and has an outer polygonal end projecting through an enlarged central aperture in a circular' plate 25. Plate 25 is attached by screws 2G tothe tops of the triangular guide members 18, these members 18 projecting beyond the, plane of the tops of their companion members 13. On the polygonal end of stein is a drum y27 .surrounding which is a split resilientband 28 having a friction facing rubbing on drum 27 and held against the drum with a jiiredetermined pressure by means of a split resilient ring 29.

Band 23 is provided with lugs 30 which pass through apertures in an annular ratchet member 31 formed with ratchet teeth adapted to engage the end of a screw 32 in the base member 10, a coil spring 33 yieldingly holding member 31 engaged with thc screw.

From the foregoing description it will be clear that when the absorber' is operating the strut seats 19, abutment 23, stem 24; and drum 27 oscillate with arm 17. Normally,

. drum 27 rotates ratchet ring 31 in one direction by reason of its frictional connection therewith, the in this movement ratcheting under screw 32, but in the reverse rotation the faces of the ratchet teeth engaging the .screw holds the ratchet ring and friction band 23 relatively stationary, the drinn slipping in the friction band. Thus in the last namd direction of rotation there is a by teeth projecting from the under sii torque tending to rotate the threaded stem 24 in the nut, or abutment, member 23. Vhen the parts have become suiciently worn to require adjustment this torque causes rotationof stem 24 ywith respect to abutment member 23 in a direction to move said member outwardly along the inclined faces of the strut seats 19, moving the seats outwardly until alllooseness has been taken up, whereupon the drum 27 will continue to slip in the friction ring until looseness again develops.

' It is desirable to produce the adjusting torque of the device in the free movement of the absorber, forthe reason that in the resistance producing movement the parts are under tension and a would be `required to produce an adjusting movement of member A23, necessitating a powerfuladjusting mechanism and an expensive construction. 0n the other hand, by arranging the parts so that the torque is produced in the free swing of the absorber', an adjusting mechanism of light and cheap construction is entirely satisfactory. The parts have accordingly been arranged to produce the adjusting torque in the free swing of the absorber, as will be clear from a cousiderationV of Figs. t and 5. As will beobserved, when arm 17 swings upwardly, F 4r, which it does freely, ratchet ring 31 is held relatively stationary by screw 32, producing a torque on stem 24 tendingto rotate the stem with respect to .abutmentmember 23 in a direction to move said abutment inwardly along the inclined faces of the strut seats 19 and hence to move said seats radially outward.

rlhe invention is susceptible of embodiment in various forms, as iis obvious that various mechanisms for jnoducing step by step adjustment of stem 2st actuated by some oscillating aloinent of the absorber can be devised. The form .described is theone at present regarded as-A preferable. but other forms may be employed and give pcrl'iaps equally as good results.

Figs. GandA show a form of the invention opcridingv on the saine principle :is that of the form just described. but having its elements sul'istantially modified. In 4this form. a conical drum l0 provid-ed with a polygonal hub fitting the. polygonal end of stem 24C. Dispoced ov drum It() is friction cone atl having a facing of fri tion material 42 and formed on its upper side with ratchet teeth adapted to be engageil .e of av plug 43 screwed in a central aperture of base member 10. Fastened on plate beneath drum 40 is a semicircular leaf spring 44 whose upturned ends the under j side of the drum and exert an upwardly directed pressure zliereon which serves to produce the required frictional engagement of relatively large torque y tdt) lli)

the cones and to hold the upper cone yieldingly against the teeth on'plug 43. This spring 44 may also if desired rserve to preventreverse rotation of stein 24. For this purpose the fre-e ends of the spring engage ratchet teeth formed on the under side of drum 40, preventing rotation of drum 40 and stem 24 with respect to disk 25 and abutment 23 and Vthe other rotating parts of the absorber except in one direct-ion, this direction beine' that in whichthe relative rotation of the stem is produced by the torque exerted on drum 40 in the yfree swing of the absorber'. It will be observed fr om the drawing that in the resistance producing rotation the teeth von plug 43 ratchet over the teeth on the upper cone 41` while in the reverse, or free rotation the upper cone is held relative stationary, producinfr a torque on stem 24 proportional to the friction between the concs, such torque being insuliicient to rotate the stem when the parts are in proper adjustment but being sutlicient to rotate the stem when any loosen-ess develops and thus move the abutment member 23 inwardly along the inclined faces of the strut seats until such looseness has been taken up. lVhen stem 24 has been thus ro? tated relative rotation thereof in the reverse direction is prevented by engagement of spring 44 with the teeth on the und-er face of drum 40.

A third formr of the invention is illustrated in Figs. 8 and 9. Here the square end of stem 24 loosely' carries two ratchet wheels and 51, the wheels being superposed and held in spaced relation by spacers 52 attached to plate 25. A sprinrr pressed pawl 52n pivoted on plate 25 engages teeth of the lower wheel 50 and a spring pressed pawl 58 pivoted on a pin 54 secured tobase member l0 engages teeth of .the upper ratchet wheel 51. The leaf spring 55 holding pawl 53 against the ratchet wheel cngages at its free end an eccentric 56 on a stud 5T passing through an aperture inr the base member and fastened eXt-eriorly by a nut 58. Froml 9 it will be seen that the faces of the upper ratchet wheel 5l are inclined with respect to a diametrical plane in such a kdirection that the line of application of the force applied to the pawl when torque is exerted on ratchet wheel 5l in a clockwise direction passes outside of the pivot 54 of said pawl, and it will be clear that the pawl 53 will be displaced to permit ratchet wheel l to rotate in clockwise direction whenever the force tt-:nflingto rotate ratchet wheel 5l in this direction eX- ceeds a predetermined value. This angle will depend obviousl)v on the face angle of the ratchet teeth and on the tension of spring 55, which latter may be adjusted by the eccentric 56. In the resistance producing'swing of the absorber, theratchet wheels cured by Letters Patent is:

and the plate 25 will rotate in a counterclockwise direction, looking at Fig. 9, pawl 53 rateheting over the teeth of wheel :El and pawl 52a and wheel'() moving together. la the free swing the wheels and plate rotate in clockwise direction, pawl 58 tending to hold ratchet whe-el 51 relatively stationary. If the absorber is in proper adjustment stem 24 will be constrained to' rotate with abutment member 23 and the other moving parts of the absorber and consequently pawl will slip over the teeth of ratchet 5l. On the other hand, when looseness has developed suiiiciently to permit adjustment of abutment member 23, pawl 53 will hold wheel 5l relatively stationary in the free swing of the absorber. causing abutment member 28 to rotate on stem 24 and thus move inwardly to take up such loosen-ess.

Three ,forms of the invention have been described. Other substantially different forms will readily occur to those skilled in.

the art. It is therefore not intended to limit the invention by any specific description.

Ha-vingthus described the invention what is claimed as new and desired to be sei l. .A shock absorber of the kind described comprising, in combination, a cylindrical casing and a core rotatable therein, brake shoes in the casing engaging the cylindrical walls thereof, means mounted on the corefor causing frictional engagement of the shoes with the casing in one swing of the core and for relieving such engagement in the opposite swing, comprising struts engaging the shoes and radially movable seats for the innerends of the struts, and means for automatically adjusting the seats when looseness develops in the absorber comprising an abutment member engaging the inner faces of the seats,

a'. screw threaded in the abutment member and friction mechanism connected to the screw tending to hold the screw-relatively stationary in one swing of the absorber but permitting free rotation thereof with the abutment member in the opposite swing.

2. A shock absorber of the kind described Y comprising in combinatioma` cylindrical casing and a core rotatable therein, brake shoes in the casing engaging` the cylindrical wall thereof, means mounted on the core for causing frictional engagement of the shoes with substantially constant force to hold the' screw lee ,such eng relatively stationary in one swing of the absorber but pern'iitting tree rotation thereof with the abutment member in the opposite swing.

8. A shock absorber of the kind described comprising, in combination, a cylindrical casing and a core rotatable therein, brake shoes in the casing engaging the cylindrical Wall thereof, means mounted on the core causing trictional engagement ot the slices with ther casing` in one swing et the core and relieving i rement in the opposite swing.y coinprising sti nts engi' jing the shoes and radialn ly movable seats i )r the inner ends ot the struts7 and means 'toi' automatically adjustiiigthc seats when looseness develops in the absorber coii'iprising an abutmentmember havingv inclined 'laces engaging the inner faces ot the seatst1 an a-.ially disposed screw threaded inv the abutment member and ratchet mechanism lfi'ictiona'lly connected to the screw tending to hold the screw relatively stationaryin the tree swing ot the core but permitting 'tice rotation thei'eot` with the abutment member in the resistance producing swing.

4. A shock absorber et the kind described incl ailing', viii combination, a cylindrical casing adapted to be secured to the trame of an automobile, a rotatable core in the casing adapted'to be connected to the aide so as to oscillateV on relative movement ot the trame a'nd aide, brake shoes engaging the inner cylindrical Wall of the casing, means mounted on the core causing i'ictional engagement oi the shoes with the casing in one direction ot rotation and relieving such engagement in the opposite direction, comprising struts engaging tlie shoes and radially n'iovable seats for the inner ends ot the struts having` inclined inner taces, and means for automatically adjusting said seats When looseness develops in the absorber comprising an abut ment member having inclined faces engaging the inclined 'laces oi the seats, a'n axially disposed screw threaded in the abutment member and ratchet mechanism trictionally connected to the screw tending to hold it relatively stationary in the tree swing ot the absorber and permitting "ree rotation tliereoic with the abutii ent member in the resistance v producing swing.

5. ln a shoc i absorber having a relatively 'stationary casing and ai rotatable core therein, brake shoes in the casing, mechanism mounted on the core causing trictional engagement of the shoes in one direction of rotation and relieving such engagement in the' opposite direction, a ratchet Wheel ricti'onally connected to said mechanism tor effecting astep by step adjustment thereor" When looseness develops, and a dog mounted on the casing adapted to hold said Wheel relatively stationary in the free rotation o't the core.v

anism when looseness developsy in the ab-- soi'ber comprising coaxial with the'V core and normally rotating therewith and a slipping connection between the screw and casing teniliiigto hold the .screw relatively stationary in one direction of rotation oit' the core.

8. In a slioclt absorber having a relatively "ionai'y base and a rotatable core, brake shoes i'i'ictionally engaging the basca mechanisiiimeunlcd on the cere causing trictioiial engagement ot the sho-es in one direction of' rotation and relieving such engagement in the opposite direction7 and ratchet devices automatically effecting a. step-by-step adjustment ot said mechanism when looseness develops therein.

i ln a shock absorber having a'relatively stationary base and rotatable trame7 brake shoes lfiictionally engaging the base mechanism mounted on the 'trame causing tric'- tional engagement oit the shoes in one direction ot' rotation and relieving such engagement in the opposite direction, and means tor automatically adjusting said mechanism comprising a Wedge engaging` said mechanism, a screw threaded in said Wedge, and

'a slipping connection between the screw and l0. In a shock absorber having a. relatively stationary base and a rotatable frame, brake slices rictionally engaging the base, mechanisin mounted on the frame causing tric-I tional engagement of the slices in one direction of rotation and relieving such engagement in the opposite clirection,aiid means ii'or automatically adjusting said mechanism vwhen looseness develops therein comprising a Wedge engaging said mechanism, a screw threaded in said Wedge coaxial with the frame and normally rotating therewith and n ratchet mechanism rictionally connected to said screw tending to hold the screw relatively stationary in one direction of' rota? tion of the frame. y Y

ll. In a shock absorber having adjustlill able friction producing mechanism, a screw adapted and arranged to adjust such mechanism to produce a predetermined friction, and a ratchet device for'automatically turning said screw to maintain such adjustment.

l2. A slioclr absorber provided with friction producing mechanism, means for adjusting said mechanism, and a'ratchet device operating on such means to take up wear in the friction producing mechanism.

13. l'shoclr absorber of the friction type provided with adjusting mechanism which includes a screw and a ratchet device for automatically turning the screw in the ordinary operation of the shock absorber.

la. ln a shock absorber, an adjusting mechanism comprising a screw member and a nut member threaded thereon, a ratchet device for automatically rotating one of said members in the ordinary operation of the shock absorber and means to prevent the rotation of the other of said members.

i5. rEhe combination with the vehicle provided with a body, an axle, and a spring intermediate the body and axle, of a shoclr absorber for damping the spring action during road travel, said shock absorber having adjusting means and ratchet mechanism for 'tively connected to the other, said absorber having` adjusting mechanism and power 0perated means for effecting adjustment intermittently and only upon the occurrence of a predetermined amount of wear in .its operating parts, the power for operating said means being transmitted thereto by said connection and resulting from relative movement of the body and axle. Y

17. A. shock absorber having two relativelv movable parts, and an adjusting mechanism, and ratchetvmeans for effecting the step by step ope ation of said mechanism upon the occurrence of relative movement between said members.

In testimony whereof I hereunto atlix my signature.

JAMES PIERCE BLDVIN. 

